1. Field of the Invention
The present invention generally relates to an ink jet recording apparatus and, more particularly, to an ink jet recording apparatus of a type utilizing a gas pressure developed as a result of electrolysis of a electrolyte or utilizing a shock wave resulting from an discharge explosion of g gaseous body developed as a result of the electrolysis.
2. Description of the Prior Art
An ink jet recording apparatus of the on-demand type capable of jetting a liquid inking medium under the influence of a pressure applied whenever the necessity arises as well known in the art, an example of which is shown in FIG. 6 as a schematic partial sectional representation. The illustrated prior art ink jet recording apparatus comprises an ink tank 102 accommodating therein a liquid inking medium 101, a displacement amplifying chamber 104 fluid-coupled with the ink tank 101 through a supply passage 103, a jetting nozzle 105 communicated with the displacement amplifying chamber 104, and a piezoelectric element 106 electrically connected to a high voltage generator 107. The high voltage generator 107 applies an electrical signal to the piezoelectric element 106 to cause the piezoelectric element 106 to deform mechanically in a direction inwardly and outwardly of the displacement amplifying chamber 104. When the piezoelectric element is deformed inwardly of the displacement amplifying chamber 104, the internal pressure of the displacement amplifying chamber 104 is increased with the liquid inking medium 101 consequently being expelled outwardly from the jetting nozzle 105 to form ink droplets 108 which successively travel towards an image receptor (not shown) such as, for example, a recording paper. This type of ink jet recording apparatus is disclosed in, for example, the Japanese Laid-open Patent Publication No. 48-9622, published in 1973.
It has, however, been found that the prior art ink jet recording apparatus of the type utilizing the piezoelectric element has the following problems. In the first place, the application of a high voltage of about two hundreds volts to the piezoelectric element results only in a mechanical deformation of the piezoelectric element within the range of several micrometers to several tens of micrometers and, therefore, a pressure chamber of an increased volume such as shown in FIG. 8 is necessitated to allow the displacement to be concentrated towards the nozzle. Accordingly, it has been difficult to construct a small-sized ink jet recording apparatus having a multi-nozzle system wherein a multiple of nozzles are disposed in an adjoining fashion. Also, since the piezoelectric element is expensive, it is also difficult to reduce the cost of a recording head.
Summarizing the foregoing, the prior art ink jet recording apparatus suffers drawbacks in that it is difficult to achieve a multi-nozzle system and a reduction in both the size and manufacturing cost of the ink recording apparatus.